Mine sweeping and disabling apparatus



July 11, 1944.

A, RONNING 2,353,360

MINE SWEBPING AND DISABLING APPARATUS Filed March .2, 1940 5 Sheets-Sheet 1 INVENTOR 4004p ,eo/v/w/va ATTORNEY ly 11, 191% A. RONNING 2,353,360

MINE SWEEPING AND DISABLING APPARATUS Filed March 2, 1940 3 Sheets-Sheet 2 INVENTOR F2 -1l:] HDOLPH lPO/VN/NG ATTORNEYS y 11, 1 A. RONNING 2,353,360

MINE SWEEPING AND DISABLING APPARATUS Filed March 2, 1940 3 Sheets-Sheet 3 INVENTOR flDOAP/V RON/V/NG ATTORNEYS i feed mechanism Fig. 5.

plane to'fiu port the Patented July 11, 1944 MINE SWEEPING AND DISABLWG APP TUS Adolph Ronnlng, eapolis, Minn. Application March 2, 1940, Serial No. 321,885

7 Claim This invention relates to improvements in apparatus for sweeping up and disabling explosive mines such as used to protect areas of theses against enemy vessels.

The primary object of the invention is to pro-- vide a mine sweeping apparatus or rig which will not only sweep up the more usual contact detonated mine, but which will be equally effective in discharging and disabling the types of mines which are detonated by vibratory or magnetic effects in their vicinity.

Another object is to provide a mine sweeping apparatus which may be .operated by either surface vessels or boats or by aeroplanes flying above the surface. A further object is to provide means ior detonating all types of mines in a small, light, practical form particularly well suited to manipulation from aeroplanes. Still another object is to provide improved mechanism for manipulating mine sweeping apparatus of this kind.

These and other more detailed and specific objects will be disclosed in the course of the following specification. reference being had to the accompanying drawings, in which- Fig. l is a view showing a mine sweeping apparatus oi my invention as pulled by boats and in use-in the sea to disable mines laid therein.

Fig. dis a, plan view, parts below the surface of the water being shown in dotted lines.

Fig. 3 is an enlarged section through one of the floats, taken along the line 8-3 in Fig. 2.

Fig. 4 is an enlarged cross section through the flexible sweeping member or cable;

Fig. 5 is a perspective view showing a mine sweeping apparatus operable by several aeroplanes flying near the water.

section through a unit such as shown in Fig. 12.

Fig. 14 is an enlarged cross section along the line "-44 in Fig. 13.

Fig. 15 is a view similar to Fig. 13 but showing a different type of disabling unit.

Fig. 16 is an enlarged fragmentary section substantially along the line |6.|6 in, Fig. 15, but sli'xlllzwlng only a central and outer portion of the Fig. 17 is a view similar to Fig. 15, but showing still another modification oi the unit.

Fig. 18 is a side elevation, partially in section, of a remotely energized electrically operating disabling unit.

Fig. 19.is a similar view of a self-energized unit.

Fig. 20 is a view similar to a left hand portion :of Fig. l, but showing the sweeping rig with attachededetonatins units of the types shown in Figs. 13-19.

Referring now more particularly to the drawings, the mine sweeping and disabling apparatus shown in Figs. 1 through 4 is adapted for operation by surface vessels or craft A and B and comprises a cable or.flexible current carrying Fig. 6 is a view showing the manner in which the flexible cable is paid out between the aeroplanes.

Fig. 'Iis an enlarged detail view of the reel and for one end of the cable used in 8 is a detail view of the connector for the other end of the cable.

. 9 is an enlarged vertical and longitudinal section through a pickup device used by an aeroof cable as shown in Fig. 5.

Fig. i0 is an enlarged elevation of an upper part of the pickup device shown in Fig. 9.

caster portion or a long span 11 is an enlarged rear elevation of a lower' member C which is connected at its ends to the vessels to be-pulledthereby through the water. This cable preferably takes the-form shown in Fig. 4, comprising a stranded wire core or conductor 6, an insulating sheath 6 of rubber or such material as used in the insulation of submarine cables, and an outer heavy covering I of wire-to protect said sheath from damage by contact with objects in the sea. At its ends the cable C carries anchors 8 which may be dropped between bitts 8 on the vessels, A and B to drag along the cable and the conductor 5 is connected at one end to a heavy dutygenerator "I carried on one vessel.

At the other end or the cable some current absorption or dissipating device I I, such as an electric welder which is readily available at anytime or place, is mounted on the other vessel and connected to conductorv 6. The return circuit is made to and through the water and as the. generator is operated it will thus be seen that a current will-flow through the cable setting up an electromagnetic field in the water thereabout. This action will be suflicient to set oil any magnetlcally detonated mines which may be in the vicinity of the cable as it is dragged through the water, itbeing presumed of course that the sensitivity of the mines is such that they will'xbe detonated by such means.

In addition the cable C may carry the usual means (not shown) for cutting ireethe contact detonatedmlnes of more usual form and the 2 cable used may in fact be the conventional cable rig for the purpose with a sheathed conductor arranged thereon in order to carry the electric currents in accordance with my invention.

and are connected thereto by short tie cables or leads l3 to support-the cable at substantially an even depth below the surface. The end portions of the cable are provided with (preferably) larger end floats l4 and the anchors 8 may be dropped to the bottom as shown in Fig.1 to

drag down the ortion of the cable outwardly of these end floats and allow the entire sweeping rig to be anchored and left standing at any time.

Light lines l5 connected to the anchors are provided with marker buoys I6 as a convenience in picking up the anchored ends of the cable and setting it in use again.

The floats I2I4 may be each, or any number thereof, provided as shown in Fig. 3 with a reel H for carrying the tie lead l3 or other cable con-- necting means. This reel is journaled by its axle l8 in a transverse opening it of the hollow body 20 of the float and a ratchet lever 2! is provided for rotating the reel to draw up the lead. The lead may be extended by releasing the latch dog 22 from the toothed ratchet wheel 23 carried by the reel.

It will be evident that the apparatus as. thus far described may be used to simultaneously sweep up the contact detonated mines in the usual manner while exploding and rendering harmless any magnetically or electrically detonated mines which may be in the vicinity. It

will thus be possible to clear a lane in the sea of i all danger by a single trip thereacross with my apparatus.

The vessels A and B are of course preferably of wooden construction so that they themselves will not set off the magnetic mines.-

It is contemplated that, the sensitivity of the magnetically detonated mines being suflicient, the cable or wire for setting up the energizing or detonating magnetic field might well be carried above the surface of the water, as shown in Fig.

5. Here the cable is shown at C and the ends thereof are carriedby aeroplanes or aircraft- A and B" with a third aeroplane E to support a center part of the cable, if desired or necessary. One plane, as that shown at A, may then carry the generator and the other the current absorption or dissipating (both not shown) device while the return circuit is made to the water by trailing ground wires shown at 24.

' The aeroplane A carrying the generator (of course this may be connectedfat either end of 25 with brackets 26 which support the axle 2! of a reel 28 for the cable. One end 28 of the cable is secured to, and electrically connected with, a metal ring 30 carried, on the. reel and the wire 3! from the generator is run through a control switch 32 to a brush 33 bearing on this C under control of the switch.- A latch dog 34 engages ratchet teeth 35 formed in one end of the reel 28 to lock the cable at any extended length while a brake lever 36 frictionally engages the'other end of the reel to prevent overrunning of the reel as the cable is unwound. A crank 31 is mounted on the reel axle 21 for reeling in the cable.

The other end of the cable C carries a ball or knob 38 electrically connected therewith, and the aircraft B carrying the current dissipating device is provided with a socket 39 mounted on a bracket 40 inwardly of the side opening 4|. Said socket has a hinged cap 42 to enclose and engage the knob 38 and retain the same by screwing down the pivoted wing screw 43, and the bracket is connected by a wire 44 to the said dissipating device (not shown). An insulating bushing 45 insulates, the bracket from the aircraft body and a handle 46 on the cable facilitates its insertion and connection with the socket 39.

.In passing out the cable C at the outset of operations the aeroplane A flies over the aeroplane B, as shown in Fig. 6, and pays out the cable until it may be grasped by. the pilot below and pulled around the wing (a short rope 41 may be used' for this purpose) and connected with the socket 39. The cable is then pulled out to the condition shown in Fig. 5, the ground wires 24 are dropped and the cable is carried over the area desired to be cleared of the magnetic mines.

The aircraft E carries a pickup device designated generally at 48 and which is used to pick up and engage a center part of the cable C after the same has been pulled out to the desired length. This device shown in detail in Figs. 9-11 comprises a tubular housing 49 which is pivotally attached at an upper end portion to a bracket 50 on the underside of the aeroplane fuselage 5i and projects at an upper end into the fuselage through an opening 52. When not in use the tubular member is swung upwardly beneath the fuselage as shown in the dotted lines,

and when in use is lowered to a downwardly and carrier strip is secured at 6! to the housing,

I and extends downwardly therefrom within a the cable) is provided within the cable opening traversing cross rib 62. At the lower extremity the spring 60 is formed to receive the hinge pin 63 by means of which the hub 6d of a pulley 65 is pivotally supported. Normally the spring 63 is tensioned to move forwardly and so present the pulley 65 forwardly of the housing 49 as. shown in the dotted line position 65a in Fig. 9, and in,

this position the pickup device when carried forward against the cable C will guide the cable downwardly into the groove of the pulley. The tension is then suflicient to carry the spring 69 back until the pulley moves directly beneath the downwardly and transversely flaring guide portions 66 of the housing 49 which thus retain the ring, to thus connect the generator to the cable cable in engagement with the pulley but permit free endwise movement of said cable.

An elongated, slightly flexible operating member or red 61 i extended through the bore of the housing 49 and at its lower end is pivotally connected at 68 with the hub 64 of the pulley forwardly of the hinge pin 63. At the upper end the member 61 is pivotally mounted and retained in the head 69 of a tubular cap which slidably and rotatably fits over the upper end of the housing. This can has slots II in opposite sides fiaring' outwardly at lower ends I2 to engage radially projecting pins I3 carried by the housing and the arrangement is thus such that, by

! rotating and adjusting the cap up and down on the housing, the member 61 may be reciprocated correspondingly in the housing. When pulled upward as shown the pulley 65 is held in cable engaging position, but when the member 61 is moved downwardly itwill swing the pulley hub backwardly and upwardly to carry the pulley rearwardly and drop the cable therefrom. This position is shown in dotted lines 6512 in Fig. 9. The

rear wall of the housing 49 may be slotted as pulley. All operations of thus picking up the cable and dropping it when finished may be carried out from within the aircraft and without interference with the normal duties of the pilot.

preferably hollow as indicated at 95 and the s rear ends and having abridle 93 and swivel, for the towing cable. The wall of the housing is ing is prevented from itself turning or s in the water by guide vanes 96.

Diametrically extending spokes or spide in the housing adjacent front and rear fe ii'ds thereof have central journals 98 for the propellers shown at I4 to provide more clearance for the member 61 as it flexes in this operation of the 99, the axles Ilioof which carry cams IIi'I within said journals as best seen in Fig. 16. Plungers I02 are slidably mounted in radially extended recesses I83 in the spokes and are urged forcefully against the cams IIIII by coil springs I 04. As this unit is pulled through the water the rotation of the propeller 99 will actuate theplungers I02 to set up a pounding action which, transmittedthrough the spokes 91 to the hollow walls of the unit, will cause a very considerable vibration in the adjacent water. This of course will detonate any vibration responsive mines in the vicinity.

Fig. 17 shows a similar mechanism, but here the housing I05, similar in shape, design and operation to that just described, has only a single Referring more particularly to Figs. 12 through 19, I also provide what may be termed individual mine detonating units or trolls which may be operated singly or in a series by a single aircraft or surface vessel.

The device shown in Figs. 13 and 14 comprises a hollow streamlined body unit or housing 15 having a swivel I6 at its forward end for the connection of a towing line or cable. A propeller shaft 11 is journaled longitudinally and axially in the housing and projects rearwardly through a bearing I8 for connection thereto of a propeller 19. A large bearing assembly 80, extended forwardly from its connection and mounting in the rear end of the housing I5, supports the forward end of the propeller shaft 11 and has a recess 8| within which the shaft carries a cane 82. Radialiy extended guides 83 in said bearing assembly 88 slidably support plungers 84 having rollers 85 contacting the cam 82 and at outer ends these plungers are connected to longitudinally extended spring arms 86. The rear ends of the arms 86 are secured at 81 to the bearing and the forward ends carry hammer 88 on outer sides and .adjacent to anvil blocks 89 secured to the walls of .the housing 15. A guide fin 90 on the housing prevents rotation thereof in the water.

This unit is pulled through the water, by means of tow cables 9| connected either to aircraft F as shown in Fig. 12, or by surface vessels of any kind. The propeller 19 is turned rapidly by action of the water and the cam 82 on the propeller shaft I1 thus rapidly thrusts the plungers 84 outward causing the hammers 88 on the arms 86 to sharply strike the anvil blocks 88. This action sets up a vibration around the path of the unit which will effect and detonate any adjacent mines of the type using vibration responsive detonators such as those described in my copending application hereinbefore identified. It will be evident that several of these units may be pulled through an area of the water infested by mines and they will eflectively render the mines harm'- less to shipping. The units may be operated either singly or in tandem formation by each pulling craft.

Figs. 15 and 16 illustrate still a different form of vibratory-unit whichcomprises a tubular or cylindrical housing 92 open at both front and propeller. I06 suported by the diametrical spoke I01 and provided of course with the vibration causing cam and plungermechanism not shown. The spoke I01 in this case is shown as horizontally extended, whereas the spokes 91 of Figs. 15 and 16 are vertically extended.

The unit shown in Fig. 18 is similar to that in Fig. 13, but additionally includes means for detonating magnetic mines. The housing I88 has rearwardly extending guide vanes I89 and the propeller III) operates in an opening III in said vanes. The propeller shaft H2 is journaled forwardly in a .bearing housing H3 and has cam mechanism, designated generally at Ill and identical to that previously described, for vibrating the hammers I I5 against the anvil blocks I IS and setting up vibrations in the water to explode vibration responsive mines in the vicinity. The tow cable I" in this case carries two wires II 8 which carry current from a generator H9, arranged in the towing craft or vessel, to the primary I28 of a transformer arranged in the housing I08. Th secondary |2I of said transformer is connected to the housing and serves to set up a magnetic field about the unit to thereby also discharge magnetic mines in the vicinity.

The unit shown in Fig. 19 also includes a housing I22 with a forward swivel connection I28 for the tow line. The propeller I24 operates in an opening I25 in the guide vanes I26, but in this case the shaft I21 turns a generator I28 supported by brackets I29 in the housing. The output of this generator is carried to the primary I80 of a transformer in the housing and the secondary I3! thereof is grounded" in order to set up the mine detonating magnetic field as the device is towed through the water. Obviously this self generating unit might also be provided with vibration producing mechanism if so desired.

Fig. 20 shows a section of the mine sweeping rig of Figs. 1 and 2 with the cable C thereof provided at intervals with individual detonating units or trolls I32 which may be any of the forms shown in Figs. 13 through 19. The rig when thus equipped will be efl'ective for disabling all types of mines whether they use contact, magnetic or vibration responsive detonators, as will be evident. Likewise individual detonating units protect by Letters Patent is:

It is understood that suitable modifications may be made in the structure as disclosed, proaataaco from the other aircraft in the water whereby a circuit will be completed to cause the flow of vided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my in, vention, what I claim to be new and desire to dissipating means, for completing the connections therebetween, said grounding wires being trailed from the respective aircraft..

2. Apparatus for disabling magnetically detonated mines, comprising a. cable adapted to be suspended at its ends between two aircraft flying parallel courses over the water and to be'carried thereby in a substantially horizontal plane above the mines in the water, a generator in one aircraft connected to one end of the cable, a cur- I rent dissipating device in the other aircraft connected to the other end of the cable, a grounding wire connected to the generator and arranged to trail from the aircraft into the water, and another-grounding wire connected to said current dissipating device and adapted to trail from the other aircraft in the water whereby a circuit will be completed to cause the flow of current through the cable, through the grounding wires and through the water between the wires to thereby establish a magnetic field sufiicient to'detonate magnetic mines in the vicinity.

3. Apparatus for disabling magnetically detonated mines, comprising a cable adapted to be suspended at its ends between two aircraft fiying parallel courses over the water and to be carried thereby in a substantially horizontal plane above the mines in the water, a generator in one aircraft connected to one end of the cable, a current dissipatin device in the other aircraft connected to the other end of the cable, a grounding wire connected to the generator and .arranged to trail from the aircraft into the water, another grounding wire connected to said currentdissipating device and adapted to trail current through the cable, through the grounding wires and through the water between the wires to thereby establish a c field sufilcient to,

detonate magnetic mines in the vicinity, the said cable being of considerable length to extend the magnetic field across a wide path in the water.

and means carried by .a third aircraft for supportably engaging a center portion of the, cable to relieve the cable of excessive sag.

4. Apparatus for disabling mines of the type detonated by electromagnetic disturbances in the vicinity, comprising in-combination, an electrically co'nducting cable adapted to be suspended between two aircraft and to be carried thereby over the mines, and means for inducing an electrical current flow along the cable to establish a electro-magnetic field about the cable and for detonating mines in the vicintiy of which the cable is passed.

5. The method of sweeping an area of water 4 to harmlessly detonate. any magnetic mines which may be present and render said area safe for the passage of a ship thereover which comprises: first calculating the residual magnetism of said ship, suspending a cable between two carrier ships, passing an electric current through said cable to induce a magnetic field equivalent to said calculated residual magnetism, and moving said carrier ships over said area while said current is passing through said cable with the cable beneath the surface of said water.

6. The method of sweeping an area of water to harmlessly detonate. any magnetic mines which may be present and render said area safe for the passage of a ship thereover which comprises: first calculating the residual magnetism of said ship, inducing a magnetic field equivalent to said calculated residual magnetism by passing an electric current through a cable, and then moving said cable over the area to be swept.

7. The method of sweeping an area of water to harmlessly detonate any magnetic mines which.

' may be present and render said area safe for the passage of a ship thereover which comprises: first calculating the residual magnetism of said ship, inducing a magnetic field equivalent to said calculated residual magnetism by passing an electriccurrent through a cable, and then moving said cable over the area to be swept, at the same time accurately guiding the movement of said cable from each end thereof.

ADOLPH RONNING. 

